Powershell Get number from string

Question

Hi all I am trying to get the number from a users id using powershell

The format we use is the first letter of the first name, first four letters of the last name and studentid so a student with the name John Smith with Id# 123456 would be jsmit123456 the problem I get if the user has less than 4 letters in their name. so using substring would give and error for those id's

I tried select-string, -match, trim, trimstart, trimend

here is my code so far

$name = Get-ADUser -SearchBase "OU=A,DC=B,DC=C,DC=edu" 
-Filter {Created -ge $checktime}     
|Select-Object SAMAccountName

foreach($object in $name){
$object
$studentid = $object.SAMAccountName.Substring(5,6)
$studentid
}

Answer 1

For readability reasons (which I sometimes find difficult with regexp) I would prefer this solution:

'john123456smith' -replace "[^0-9]" , ''

123456

Replace everything which is not a number, [^0-9], with nothing, ''. This does not involve the $1 syntax (the string matched by the regex)